Uses
Dichloroborane Diethyl Etherate is a hydroborating agent providing access to alkyldichloroboranes and alkenyldichloroboranes; reagent for deoxygenation of sulfoxides and cleavage of cyclic acetals.
Synthesis
The preparative method of Dichloroborane Diethyl Etherate (BHCl2.OEt2): An approximately 1.5 M solution in diethyl ether can be prepared by the reaction of Lithium Borohydride with Boron Trichloride. The neat reagent can be isolated by removing excess diethyl ether. It is a colourless liquid, 6.6 M in BHCl2, containing about 4-6 mol % of BCl3.OEt2 as impurity. Less conveniently, BHCl2.OEt2 can also be prepared by reacting BCl3 with Diborane in the presence of diethyl ether. The deuterated reagent is known.
Precautions
Corrosive, flammable, air- and moisture-sensitive liquid. Reacts violently with water. The reagent is not stable over long periods of time, cleaving the ether solvent at a significant rate, even with storage at 0 °C. The neat reagent has not been stable for over 2 days at rt. Handle in a fume hood.
